CONSTRUCTION SAFETY

Safety and reliability are built into the NEXUS Project before, during and after the construction phase. As with everything we do as a company, safety is at the forefront of this process. Our dedication to continuously improve our operational safety practices stems from our relentless focus on protecting the people within the communities where we operate, our employees and the environment. While we already have a strong safety record, our goal is zero incidents, as no incident is acceptable.

Pipelines are America’s lifelines, and they operate safely every day across the country. In fact, according to the U.S. Department of Transportation (DOT), natural gas transmission pipelines are the safest mode of energy transportation. In order to maintain this level of safety, we are employing a number of redundant, overlapping layers of protection during the construction process and throughout the life of the Project. NEXUS construction and environmental inspectors, as well as FERC third-party compliance monitors, are overseeing the day-to-day construction activities. FERC inspectors and state environmental inspectors are also periodically on site to inspect the work and review construction records.

We take care to limit our footprint and actively manage potential effects on communities and the environment. This includes using pre-existing rights-of-way and access routes where possible to construct the pipeline. When we encounter large rivers or sensitive crossings, horizontal directional drilling (HDD) technology allows us to continue the pipeline route without disturbing the native environment. We work closely and continuously with regulatory agencies and comply with environmental regulations at all times. Following construction, we minimize our long-term impact to the land along our pipeline through reclamation activities, including soil replacement, seeding, and tree planting.

Before digging begins, grading is required to provide a relatively level surface to safely operate heavy equipment, such as backhoes and wheel trenchers. DOT requires the top of a pipeline to be buried a minimum of 30 inches below the ground surface. This depth increases at river and road crossings. If large quantities of rock are found during trenching operations, the crew uses specialized equipment and techniques to remove the rock in accordance with state and federal guidelines to ensure safety.

Welding

Each weld on the pipeline is made by a qualified welder in accordance with welding procedures and is visually and non-destructively tested (i.e. by radiography and/or ultrasonic) to ensure integrity. Welds are inspected and evaluated according to specified inspection procedures, standards, codes and drawings. The pipeline is being constructed using high-strength carbon steel, manufactured in accordance with DOT pipeline regulations.

Coating

The coating process is typically completed before the pipe segments are delivered to the construction site. The entire length of the pipeline is protected by a thick layer of specialized epoxy coating that prevents corrosion, abrasion and other damage. Prior to lowering the pipe into the trench, specialized equipment calibrated to the proper voltage is used to inspect the pipeline and ensure it is free of defects.

Hydrostatic Testing

As various sections of the pipeline are completed, they are filled with water and pressurized to a point higher than the maximum pressure at which the pipe will be operated. This test pressure is held for a minimum of eight continuous hours and catalogued to ensure the integrity of the pipeline. Hydrostatic testing is the final construction quality-assurance test before the pipeline is put into operation. Requirements for the test are also prescribed in DOT’s federal regulations.